Electrochemical device

Abstract

An electrochemical device includes a positive electrode, a negative electrode, a separator, and a lithium-ion conductive electrolyte. The positive electrode includes a positive electrode current collector, and a positive electrode mixture layer. The negative electrode includes a negative electrode current collector, and a negative electrode mixture layer, and the specific surface area of the negative electrode mixture layer is 10 m2/g-70 m2/g. The negative electrode mixture layer includes a negative electrode active material, and a binder that binds the negative electrode active material to the negative electrode current collector. The binder contains at least a first component, and may contain a second component. The first component is at least one selected from the group consisting of carboxymethyl cellulose and a carboxymethyl cellulose salt. The ratio of the mass of the second component to the mass of the negative electrode mixture layer is 0%-1%.

1 . An electrochemical device, comprising
 a positive electrode, a negative electrode, a separator, and a lithium-ion conductive electrolyte, wherein   the positive electrode includes a positive electrode current collector, and a positive electrode mixture layer which is supported on the positive electrode current collector and into which anions are reversibly doped,   the negative electrode includes a negative electrode current collector, and a negative electrode mixture layer which is supported on the negative electrode current collector and into which lithium ions are reversibly doped,   a specific surface area of the negative electrode mixture layer is 10 m 2 /g or more and 70 m 2 /g or less,   the negative electrode mixture layer includes a negative electrode active material, and a binder that binds the negative electrode active material to the negative electrode current collector,   the binder contains at least a first component, and may contain a second component other than the first component,   the first component is at least one selected from the group consisting of carboxymethyl cellulose and a carboxymethyl cellulose salt, and   a ratio of a mass of the second component to a mass of the negative electrode mixture layer is 0% or more and less than 1%.   
     
     
         2 . The electrochemical device according to  claim 1 , wherein a peeling strength of the negative electrode mixture layer from the negative electrode current collector is 0.015 N/mm or more. 
     
     
         3 . The electrochemical device according to  claim 1 , wherein a ratio of a mass of the first component to the mass of the negative electrode mixture layer is 3% or more. 
     
     
         4 . The electrochemical device according to  claim 1 , wherein the first component includes an ammonium salt of carboxymethyl cellulose. 
     
     
         5 . The electrochemical device according to  claim 1 , wherein the specific surface area of the negative electrode mixture layer is 20 m 2 /g or more and 60 m 2 /g or less. 
     
     
         6 . The electrochemical device according to  claim 1 , wherein the negative electrode mixture layer contains Ketjen black as a conductive additive. 
     
     
         7 . The electrochemical device according to  claim 6 , wherein a ratio of a mass of the conductive additive to the mass of the negative electrode mixture layer is 2% or more and less than 15%. 
     
     
         8 . The electrochemical device according to  claim 1 , wherein a specific surface area of the conductive additive is 800 m 2 /g or more. 
     
     
         9 . The electrochemical device according to  claim 1 , wherein the negative electrode active material includes hard carbon. 
     
     
         10 . The electrochemical device according to  claim 1 , wherein a surface layer portion of the negative electrode mixture layer has a first layer containing lithium carbonate. 
     
     
         11 . The electrochemical device according to  claim 10 , wherein
 the surface layer portion of the negative electrode mixture layer has a second layer containing a solid electrolyte, and   at least a part of the second layer covers at least a part of a surface of the negative electrode mixture layer via the first layer.   
     
     
         12 . The electrochemical device according to  claim 11 , wherein
 the second layer contains lithium carbonate, and   an amount of the lithium carbonate contained in the second layer is smaller than an amount of the lithium carbonate contained in the first layer.   
     
     
         13 . The electrochemical device according to  claim 1 , wherein the separator contains an olefin-based resin.